Aiming at the acoustic field waveform of the resonator driven by magnetostrictive transducer,based on the theoretical analysis of the standing wave field in the theoretical analysis tube,the finite element software ATILA was used to analyze the magneto-mechanical coupling and gas-solid coupling analysis,and the transconductance was obtained by simulating the acoustic field waveform of the resonant cavity driven by the magnetostrictive transducer.The magnitude of the sound pressure produced by the resonant cavity under the six alternating current excitation of 1 000~6 000 Hz is obtained.The displacement of the radiator plate of the transducer with six alternating currents is extracted and the sound pressure value of the resonator is obtained.Numerical Curve of displacement value of radiation plate.It is found that the temperature of the resonant cavity can be increased by increasing the current frequency,so as to improve the cooling capacity of the thermoacoustic refrigerator.The experimental results are in good agreement with the simulation results,which verifies the accuracy of the simulation results and also provides an accurate basis for the actual working conditions.

In order to provide a theoretical basis for designing water-saving toilets,the internal flow-field of siphon pipeline was simulated by the Fluent software to study the flow law of gas-liquid two-phase flow.The VOF model and the RNG k-ε model were applied to study the internal pipeline structure affected to the properties of siphon.The numerical simulation results showed the distribution of the internal gas-liquid two-phase flow state,the pressure and the flow velocity.Through the cold model experiment,validates the reliability of numerical simulation.The results also showed that:1)the gas-liquid two-phase flow numerical simulation was effective in analysis of siphon pipeline;2)the negative pressure and velocity magnitude had a direct effect on siphon action;3)the negative pressure was formed by high-speed flow from the jet;and 4)the pressure gradient was caused by jet and outlet confirmed stability of the siphon.

The standard solution is an important engineering problem solving tool in TRIZ,and the standard solution knowledge base is the pillar of standard solution.In order to improve the efficiency of engineering problem solving,based on 76 standard solutions and data mining technology to obtain patented literature resources implied depth of knowledge.Creating the process of building the standard solution knowledge base on the data mining technology,to achieve the depth of patent knowledge digging.In order to make up the deficiency of CAI software in case retrieval,uses Case-based Reasoning (CBR) technology to retrieve the innovative examples in the standard solution knowledge base,select several instances with high similarity,realizing the function feature replication,reorganization,mutations based on the functional feature analyse,resulting in innovative solutions.To create a standard solution knowledge base application process,standardize the use of standard solution knowledge base,using the design examples of bicycle to verify the feasibility of the process.

The inherent hysteresis nonlinearity of MSMA influences MSMA drive positioning accuracy to Ni₂MnGa magnetic shape memory alloy as the research object,multi field coupling system using MSMA control experiment,experimental temperature and magnetic field strength,stress,temperature,and record the magnetic field and the experimental data of MSMA strain.The electromagnetic field simulation of the MSMA drive device model magnetic circuit is carried out at Ansys Maxwell,and the optimum coupling magnetic field strength is obtained.According to the experimental data,using the law of conservation of energy and the thermodynamics theory,construct multi field coupling model MSMA,prediction of multi field coupling variable curve,the best coupling conditions of MSMA actuator,and provides a theoretical basis for the high precision positioning MSMA drive.

Additive Manufacturing(AM) is a manufacturing process through which a 3D component is produced by consecutively addingmaterial.One of the most promising AM processes is SLM.In SLM a laser completely melts metallic powder particles togetherforming a 3D component.SLM is known for its freedom of manufacturing constraints allowing complex geometries and highmaterial efficiency.Topology Optimisation(TO) is an optimisation type that calculates the optimal material distribution for agiven problem.The combination of SLM with TO is being developed to create lightweight components.In this work,the whole development process,from optimisation to design,production and testing is addressed.Initially,an aircraft bracket topology wasoptimised to be produced by means of SLM.The TO solution was interpreted and designed for AM.During the interpretationand design process,a design methodology was defined in order to facilitate and make more accurate the TO solution design andmake it ready for AM.After the optimised component was produced,metrological and mechanical tests were performed in orderto validate the final design and the computer analysis.The optimised component showed considerable weight reduction with anincrease of the factor of safety.The experimental tests revealed a good relation to the computer analysis evidencing,however,room for improvement,both in the computer model and the experimental tests.

Aim at the precise control for a new type of slurry extrusion system,according to the different state of motion of the extrusion system in the work process,the relative motion relationship between various parts of the system is analyzed.Construct stepper motor and the extrusion rod kinematics model:θ-s model,v-w model.Based on the θ-s model,draw the trajectory and workspace of the extrusion rod using Matlab software and analyze its motion characteristics.According to the kinematic model of the extrusion rod and the continuity equation of the fluid,the motion control model of the system is built.Finally,the feasibility and effectiveness of the control model are evaluated according to the prototype experiment,and the actual output quality is less than 0.1~0.15 g,but the linear variation is better,less than 0.05 g at best.This provides a reference for the introduction of the later motion control algorithm.

Existing maintenance models are lacking in relevance due to the neglect of the operating characteristics of these devices during the establishment process.The scheduling of maintain resource should be taken into account when formulating the equipment maintenance plan as the overall optimal management idea being popular.Based on this,it takes the equipment that does not allow downtime during operation as the research target,and establishes the sequence preventive maintenance model by using the relationship between equipment reliability and service age.Secondly,In order to optimize the maintenance plan under the condition that the maintenance resources are fixed,it establishes the maintenance center cost minimization model according to the maintenance plan of the equipment based on the analyzing of cost factors for the maintenance center.Finally,it takes a medical monitor that its failure time subjects to Weibull distribution as an example.The simulation results show that the model can meet the maintenance of the equipment and proves the feasibility of the proposed joint optimization method.

Studying on the framework of cluster enterprises competitiveness is to integrate the cluster environment,cluster resources and enterprise competitiveness.Based on industrial cluster perspective,enterprise cluster competitiveness analysis model is established and then competitiveness improvement of enterprise bringing from cluster development is researched.Ultimately,the enhanced level and scope of the improvement on the core competitiveness of enterprises made by cluster is confirmed to help enterprises choose the better cluster.Moreover,it is also conducive for the cluster managers to adjust resources aiming at competitiveness’s current situation of most enterprises in the clusters and then to achieve the goal of enhancing the overall competitiveness of the cluster.Firstly,use the data collection method to construct the priority-degree evaluation model of cluster enterprise competitiveness,which takes all the important cluster factors of promoting and inhibiting enterprises competitiveness into consideration.Secondly,in order to realize the combination between theory and practice of extension model,establish the system dynamic model of cluster enterprise competitiveness,through whose simulation analysis can track the influence mechanism of the extension evaluation index model on the cluster enterprises competitiveness.Then,determine the key variables by gradual deletion method,so that the extension model can be modified to improve the accuracy of the feature selection and the final result analysis.Finally,verify the practical significance of the model with an example.

In order to reduce the delay in ship operations,improve the operational efficiency of transportation equipment and decrease the cost of ship operations at automated container terminals,the double trolly quay crane was adopted to transport containers in coordination with AGVs.A mixed integer programming model is established for assigning optimal delivery and pick-up tasks to AGVs in considering the buffer of quay,which target was minimizing the total travel time,empty rate of AGVs and the delay of Quay Cranes(QCs) with time-window constraints for the trolley in landside.The numerical experiment is performed by CPLEX Optimization Studio.It verified that the double trolley quay crane has the superiority in AGV scheduling optimization through four analysis of results from different aspects.And the number of buffer capacity under the quay crane,the number of AGV and optimal scheduling of AGV with double trolley quay crane were found out.

Power system is core component of pure electric vehicle,the vehicle performance is closely related to the dynamic system matching design.Unreasonable matching design not only affects the vehicle dynamic performance playing,but also reduces the travel distance of vehicle.Accurate and reasonable matching design is hot and difficult point in electric vehicle research.According to the theoretical knowledge of automobile and the requirements of vehicle power performance,the parameters of the vehicle power system are designed.With the help of MATLAB/Simulink and ADVISOR simulation software,the dynamic performance and continuous driving range of the vehicle are simulated under multi-working conditions,improve the accuracy of simulation results by comparing and analyzing simulation images.The results show that the dynamic system parameter matching design is reasonable,and all the performances meet the design requirements.

Based on GB 20072—2006 and rear-end collision in real life,finite element model of a passenger car with a dummy in rear-end collision is established,which correspond to car-sled model and car-car model respectively.Each model contains two types:original model and model without rear bumper.The simulation shows that deformation of structures of rear vehicle and injury of passenger increase heavily in model without rear bumper.The situation also happens to car-car model.In general,structural deformation and human injury in car-car model are higher than that in car-sled model.Thickness of rear bumper is optimized via moving least square response surface method and Adaptive Response Surface Method(ARSM).It is expected that to light weighting of rear bumper and improve injury of passenger.

ARIZ is the method used in the TRIZ theory to solve complex problems in products.In view of the problem that copper exposure seriously affects product quality in the process of bead wire hanging glue,ARIZ algorithm was applied to carry out innovative design of the production process,and experimental verification was carried out.Through the analysis of the main causes of copper exposure,the technical system where the problem occurred was determined,and the functional model of the system was established.Aiming at the problems existing in the technical system,systematic analysis was carried out by using the methods of contradiction analysis and material-field analysis.A series of innovative schemes were formed by applying the inventive principles,standard solutions,smart little people method and other tools.Combined with the actual production,the innovative solutions were evaluated and the optimal scheme was obtained.The innovative design of bead wire hanging process scheme verifies the practicality and high efficiency of ARIZ algorithm in solving complex product problems.

Taking a motorcycle frame as an object,the collection of practical road load spectrum in the proving ground and the treatment of equivalent damage are introduced to compress test cycle significantly.Using the motorcycle road simulator of two channel test stand,taking the load spectrum for initial input,the closed real road excitation equivalent input signal is obtained by iteration.By using the CATIA software and multi-body dynamics simulation software ADAMS,the virtual rigid-flexible coupled road simulation test platform is built with reference to the actual motorcycle frame road simulation test bench.Simulation analysis is conducted with the achieved road simulation excitation spectrum as input and the outcomes are verified by road simulation test results,thus the virtual vibration test method for motorcycle frame based on measured load spectrum is established,an effective methods for motorcycle frame structure design and performance assessment is provided.

In order to reduce the development cycle of the bearing housing and improve the design efficiency,the three-dimensional parametric design of the high-speed and heavy-load bearing housing is carried out by means of modern digital design.Taking UG10.0 as the three-dimensional parametric design platform.The physical thermal analysis method is used to establish the mathematical relationship between the deepness of cooling groove and the bearing dimension,bearing speed and load.The mathematical relationship is used to establish three-dimensional parametric model that have the relationship between the deepness of cooling groove and the bearing dimension,bearing speed and load.The finite element analysis and verification are carried out by using NX FLOW.The results show that the parametric model obtained by changing the geometric size or load parameters satisfies the actual working requirements,and the intelligent three-dimensional parametric design of the high-speed and heavy-load bearing is realized.It provides the same new product development with a smart and efficient design method.

Based on ANSYS parametric design language APDL,the parametric finite element model of wind turbine main shaft was established with taking the structural dimension parameter as the variable.At the same time,the finite element analysis command file of main shaft was compiled.On this basis,the DOE(Design of Experiment) for main shaft was executed by using ISIGHT combined ANSYS,and the influence of the dimension parameters on the maximum working stress of main shaft was gained.The 5 dimension parameters which have greater influence on the maximum working stress of main shaft were selected and a two order response surface model for the parameters selected and the maximum working stress was built by using the approximate modeling function of ISIGHT.According to the response surface model gained,the static strength reliability computation program of main shaft was compiled by MATLAB.Finally,on the basic of ensuring the structural reliability level meets the requirement,the dimension optimized design of main shaft was carried out through the optimization module of ISIGHT.The optimization results showed that the optimization effect of the MISQP optimization algorithm was the best, and the volume of wind turbine shaft was reduced by 2.47 %.

The micro vibration of spacecraft structure will affect its accuracy.Bolt connection is widely used in the structure of the spacecraft,which will affect the strength and damping of the whole structure,leading to a certain nonlinear phenomenon.The aluminum honeycomb panel with bolt connection was studied,and the contact mechanics model is introduced to characterize the stiffness and yield stress of the Iwan model.And multi-scale method is used to find the solution to this system,finally we obtain the nonlinear frequency response function.Based on the theoretical model,we establish a system of finite element model of connection part substitute Iwan model and the corresponding experiment was carried out.At last, verify the correctness of the theoretical model so that we provide a reliable basis for the further research of the spacecraft vibration problem.

Teeth distance is a key parameter for bi-metal band saw blade application.Crook cutting is mainly caused by deformation of the back blade according to force analysis in the sawing progress.The deformation is connected to the cutting and feed force which is influenced by teeth distance.A formula for the relationship between the cutting depth parameter and teeth distance has been build.On the ground of the results from calculation and experiments,it finds that adding teeth distance will descend the cutting and feed forces on the whole blade but increase those on the single teeth.

The complex natural stone,which can be milled and carved,refers to natural stones that exist independently in nature and have natural shapes and very delicate grains.The natural stone has the characteristics of complexity,regularity and individuality,and the size varies greatly,which is very difficult for locating clamping,and the clamping efficiency is low.At the same time,the natural stone with high hardness,uneven,brittle material characteristics,and a high cutting tool speed,which make machine tool vibrating,it’s difficult to guarantee the clamping reliability when carving and milling.The high efficient clamping method for the processing of complex natural stone carving and milling is studied.First of all,the characteristics of the carved and milled processing of complex natural stone and the difficulty of clamping are analyzed,putting forward the “232” clamping method,the clamping method contains two fixed support surfaces,three universal dynamic supports and two universal dynamic tensioners,and a set of complex natural stone fixture based on “232” clamping method is designed.The fixture can quickly and reliably locate and clamp the complex natural stone,improve the clamping efficiency and reduce the labor intensity,which provides a method of high efficiency clamping of the natural stone for enterprise.Finally,taking Tuojiang jade as an example,the practical application is made,a good application effect is obtained,and the application foreground of the method is demonstrated.

With advantages of light weight,high pressure resistance and high density of hydrogen storage,the fully-wrapped carbon fiber reinforced cylinders with an aluminum liner for the on-board storage of compressed hydrogen as a fuel for land vehicle with nominal working pressure of 70 MPa is one of key components of hydrogen supply system for hydrogen fuel cell vehicle,and become the first choice of the fully-wrapped carbon fiber reinforced cylinders with an aluminum liner for the on-board storage of compressed hydrogen as a fuel for land vehicle.Stress distribution of the cylinder in specific pressure processes is achieved through finite element method on fully-wrapped carbon fiber reinforced cylinders with an aluminum lined with nominal working pressure of 70 MPa of water capacity of 27 liters.In order to provide some basis for the design of cylinders,mastering the stress distribution rules of cylinders under various pressure conditions is very important.

In order to research the influence of effective grainsin the vitrified bond CBN grinding wheel surface on wheel grinding performances,which is in low concentration,effective grains percentage model was established firstly,and a new method of detection and statistics for effective grains was proposed.And then,a series of grinding experiments for six wheels in different concentrations and in different levels of granularity were carried out.The results demonstrated that decreasing concentration of wheels can increase the percentage of effective grains in static state,and improve grain utilization,nonetheless,the grinding performances deterioratein the condition of concentration below 30 %.At the same time,increasing concentration of wheels can increase the number of effective grains in static state,and enhance wheel grinding ability,never the less,the grinding performances cannot gain further advance and the wheel cost efficient will drop seriously in the condition of concentration above 70 %.Besides,in the comparison of low concentration grinding wheels in different levels of granularity,fine grain wheel can gain better performance under the same condition.

A thickness detection method based on the dispersion characteristics of the Lamb wave is proposed to solve the detection problem of the boiler scale thickness.Firstly,the fluctuation model of Lamb wave in the aluminum-scale double-layer elastic structure is established,and the semi-analytical finite element method is adopted to solve the characteristic equation of Lamb wave in the model,and the dispersion curve of the Lamb wave which changed with the scale thickness is plotted.Secondly,a two-dimensional electromagnetic ultrasonic simulation model of aluminum-scale is established.The Lamb wave of S0 mode is excited by electromagnetic ultrasonic transducer in aluminum plate,and the waveform curve under different acquisition points is got.Finally,through the analysis of the dispersion curve and the waveform curve,the Lamb wave velocity of the low frequency S0 mode becomes slower with the increase of the thickness of the scale,and the Lamb wave velocity of the high frequency S0 mode becomes faster and the amplitude of the signal wave group decreases.The results show that the thickness of the boiler scale can be detected by S0 modal Lamb wave velocity and amplitude change.

To improve the image segmentation accuracy of machine vision system, a Multi-Neural Network (MNN) segmentation algorithm based on wavelet transform is proposed. The algorithm consists of three phases: multi-neural network region division, feature extraction and classification. The training region and the region to be classified near the boundary of the initial segmentation are divided into several small regions by the polygon fitting algorithm. The feature extraction is achieved by the extension of images which are the result of wavelet transform of the original image. The neural network classifier classifies the pixels in the region to be classified to target pixels and background pixels, and to obtain the segmentation results, some post-processing are performed.The multi-neural network algorithm and the threshold segmentation algorithm are compared with the segmentation accuracy of bearing defect image. The result shows that the Pixel Error (PE) of the multi-neural network algorithm is reduced by 75 % than the threshold segmentation algorithm. Segmentation accuracy is improved significantly.

Based on the classical theory of standard working hours,in the purpose to measure the standard working hours more conveniently,using video technology to record the working scene,and then use Double-E software or classical IE methods MOD toestablish the determination process of standard working hours combined with job evaluation method,this determination process can calculatethe standard working hoursquickly under different targets.This method was verified by an example of an enterprise’s hands operation,meanwhile compared the advantage and disadvantage between Double-E software and MOD method on the analysis of the video.It can be drawn that Double-E software can be used to eliminate invalid actions and calculate a reasonable standard working hoursquickly.The MOD is better to improve the efficiency of enterprise by improving action and remodelingaction process.

In order to improve the assembly efficiency of the oxygen sensor protective cover and pedestal,and to ensure the reliability of equipment operation,the assembly machine and its control system for oxygen sensor protective cover-pedestal were designed.The whole scheme and working principle of the assembly machine were analyzed in detail,the key parts of the system were designed,including the pushing mechanism and the assembling mechanism.The hardware structure of the control system was introduced,including the main control unit,the system driver module,sensing module and the touch screen.The software part of the control system was described concretely,the control flow of PLC was elaborated,GT-Designer3 was used to design the operation interface of the system to realize human-computer interaction.The equipment has been put into use,and actual operation results show that the assembly machine is stable in performance,the assembly efficiency is improved by 25.3 %,and the assembly yield rate reaches as high as 99.96 %,which meets the production requirements.

Aiming at the problem of failure diagnosis of diesel engine working status based on steady process and linear system statistical method,a fault diagnosis method of diesel engine based on feature extraction and correlation analysis is proposed.Firstly,the time domain,frequency domain and time-frequency characteristics of vibration signals of diesel engine cylinder head under different working conditions are extracted,and a standard characteristic matrix and an unknown characteristic matrix are established.Relevant analysis methods are used to analyze the correlation between different working condition signals.Finally,a model six diesel engine test bench was used to simulate the four conditions of normal,collision cylinder,misfire and small head tile wear respectively.The experimental results show that this method can accurately diagnose four operating conditions of normal,collision cylinder,misfire and small head tile wear,and prove the effectiveness of this method in diesel engine fault diagnosis.At the same time,sensitivity coefficients are used to evaluate and rank the fault features.The sensitive characteristics of the fault of the impact cylinder and the small head tile wear are mainly concentrated in the time domain,while the normal and misfire are also concentrated in the time and frequency domains.

Aiming at the problem of a shortage both in strength and stiffness of the line gear in the traditional mechanical transmission field,combined with the characteristics of the space curve meshing of the line gear,a kind of staggered axial gear transmission mechanism with high-strength and large transmission ratio is designed,which can be used to the traditional machinery.The experimental results show that this kind of line gear with high-strength structure obtained by 3D printing equipment,has high shape-accuracy and high dimension-accuracy,which can perform meshing transmission continuously and stably.